Long-distance-telephonic apparatus.



V. TARDIEU, LONG DISTANCE TELEPEONIG APPARATUS.

APPLICATION FILED NOV. 5. 1904.

Patented Apr. .26, 1910.

2 SHEETS-SHEET 1.

avwen roz Wiheooea 9 7 I v. TARDIEU. I LONG DISTANGE TELEPHONIGAPPARATUS;

APPLICATION FILED NOV. 5, 1904.

Patented Apr. 26, 1910.

2 SHEETS-SHEET 2.

anuenl'ov UNITED STATES PATENT OFFICE.

VICTOBIEN TARDIEU, F ARLES, FRANCE.

LONG-DISTANCE-TELEPI-IONIC APPARATUS.

956,228. Specification of Letters Patent Patented Apr. 26, 1910.

Application filed November 5, 1904. Serial No. 231,601.

To all whom it may concern: knocks that are audible at a moderate dis-Be it known that I, VICTORIEN TARDIEU, tanc-e, if the necessaryattention is given. doctor of medicine, a citizen of the Republic Theseknocks or shocks are evidently the of France, residing at Arles, Rhone,in the cause, that sound is clearly reproduced by 5 Republic of France,have invented certain my apparatus even at the greatest distances,

new and useful Improvements in Long-Dis though the individual shocks areno more tance-Telephonic Apparatus, of which the discernible at suchdistances. The sound following is a full, clear, and exact descripthenseems to be an uninterrupted even tion. sound without shocks. If severalof the 10 This invention relates to apparatus for the above hollowbodies or cylinders of equal distinct transmission of sounds morepardiameter are placed together, only clear ticularly over longdistances and for reproharmonic upper tones are produced by them, ducingmusical or the like productions in provided that the heights of theseveral cylshort in all cases, in which a very clear transinders showharmonic proportions. The

15 mission of sounds is required. best effect viz. the greatestreinforcement In my apparatus the distinct transmission of Sound 8 p tan d, f he proportion is of sounds is obtained by the'use of partly hequlnte 0r treble (accordlng to closed pipes or tubes closed at both endsor K gl- The apPhcatloh of these 1 of hollow bodies, especially in theform of 0113185 to telephonlc apparatus g Y great 20 low cylinders,though their form is not and uheXPeCted result? but qu s E1180essential. In such pipes or tubes, etc., sound a p r icular constructionof my apparawaves entering them or beating against them P e tS haveshown, that the are converted as described ater on into efiect 0f81.1011 p o e app r u 18 sound waves having a higher rate ofvibramaterlany lhcreased, 1f 1t 15 Egulated 25 tion per second. Theselatter produce electuned f r h o nd 01 note, which may trical impulsesin a microphone, which pass beregarded as the bas1s of the human voice,t th t l h receiver7 here they are being the note, which occurs mostfrequently. reconverted into sound Waves, the receiver h t ne or note 15a g of 384 to 424 also consisting of pipes or hollow bodies, etc.vlblflfilons p O C All parts Ofthe tele- 30 Th Conversion f Sound wavesf a 1 phonioapparatus must be proportloned to rate of vibration persecond into such of a Sll1t g. f o her O tone, o higher rate isregulated by physical laws, lIlstahce a ,7 h Should prove 111K191 th twere fi t b d b fl l h l d certain circumstances a better base theprothen minutel exa ined by R dolf Kti i portions would have to beselected according 35 in Paris and described by him in his work: to

Qnelgues Ewpm'ences dzlcoustz'que Paris I am aware that 2HJPQTMUS areknown: the 1882, pages 113 H, d 125 ff construction of which allow ofthe suppo- In closed hollow bodiesfor instance low sltloh, that Soundsof a low Fate of Vibration cylinders employed in the transmitter acacohlerted into souhds of h f rate) 40 cording to myinventioninterterences are Consequence 9 h ahle bodies with a formed inconsequence of the air waves beh g rate of Y f belng lhtroduced ingreflected inside the hollow bodies and thelelh; lhstilhce a lmcl'ophohethen crossing each other. The sounds thus lmhslhltter, 1h Whlch Vertlcaltubes of produced by the interferences were called s lengtharlhngeiclose together receive 45 by Helmholz additional anddilferential the souhd Waves, Whlch P gh them Sounds d hav a fa hi h t fimto the d aphragm and cause their vibration. tion per second than th riinal Sounds i Then microphone transmitters and telephone fact they mayreach the eighth octave of the FBCQIVBIS known, 1h Whlch the Vlhmhhglatter. Konig however doubts the existence agents COIISISt f 1111prings, the effect 50 of additional anddifi'erential sounds and calls 0fWhich is c ea ed by arranging their the sounds caused by theinterferences sons length in such manner that each of them Videgbattcments. It is quite certain howbrates o n S un of the diatonicscale. ever that the hollow bodies produce besides l t se apparatus ho eer do not Show higher harmonic sounds slight shocks or hollow bodies ofharmonic proportions filled with air, in consequence of which nointerferences or shocks are produced, on which the superior action of myapparatus depends.

The accompanying drawings represent an embodiment of a telephonicapparatus according to my invention, which I have se lected forillustration, but to the details of which I do not confine myself. Inthis example the arrangements peculiar to my invention their effects andtheir advantages are shown. The apparatus consists of the microphonetransmitter and the telephonic receiver.

Figure 1 represents avertical axial section through the microphonetransmitter. Fig. 2 is a vertical axial section through the receiver andFig. 3 is a front view of the receiver without the cover and ear piece.

The microphone transmitter, Fig. 1, contains the space or cylinder forreceiving and transmitting the sound between the two car bon plates 2and 3. In front of the carbon plate 2 there is a metal plate 4 andbehind the carbon plate 3 a metal plate 5, by which two hollow bodiesbetween the plates 2 and 4, and 3 and 5 are formed. Plate 4 is firmlyfastened between the mouth piece 9 and ring 10, plate 2 between rings 10and 18, plate 3 betwen rings 18and 19, and plate 5 between ring 19 andthe back 16. The plates or disks especially the metal plates should haveno play, because a more intense tone is produced, if they are firmlyscrewed.

The front side of the middle part of the carbon plate 3 has a truncatedconical excresence S with a projecting rim 95 and four rows of circulargrooves (5. The section of these grooves 6 is of a V-shape, so that theycan be filled with balls 7. \Vhen plate 3 is in a vertical position theballs in any same groove 6 just touch each other, a. small spaceremaining between the two uppermost balls of each row. In this verticalposition of plate 3 the balls 7 have some play for moving forward andbackward and are kept by the carbon plate 2 from falling out of theirgrooves. The four grooves 6 contain (3, 14, 20 and 25 or together carbonballs. In the rear side 16 of the microphone, an opening 17 is formedfor enabling the metal plate 5 to vibrate freely. A wire gauze disk 15is fitted over the back 16 and another wire gauze disk 12 is let into agroove of the mouth piece 9 in order to protect the interior of themicrophone from damage. The wire gauze 12 retains the moisture of thebreath and leads the same to a small tube 13, for which purpose a smallgroove 14 is formed in the ring 10. The two carbon plates 2 and 3 bearupon an ebonite ring 18 against which they are held by the screwed rings10 and 19. A ring 20 in which the microphone can be rotated has two arms21 through each of which passes a screw 22 for properly adjusting themicrophone. In consequence of this arrangement the microphone can bewashed and maintained free of germs. Thus in the event of an epidemiceveryone can have his own mouthpiece and front metal disk 4, as theseparts can readily be replaced by others without in any way interferingwith the microphones action.

The receiver shown at Figs. 2 and 3 consists of a box or casingof thesame internal diameter as that of the microphonewhich contains theelectro-magnet, the membrane and the other necessary parts. The casingconsists of a metal ring 23, into one end of which is screwed a cap 25,having an opening 24, while into the other end is screwed a cover 26. Anear piece 27 is screwed on to this cover, which also has an opening 28,the diameter of this being somewhat smaller than that of 24. The cover26 is formed arched outward toward the ear piece 27 in order tostrengthen the sound waves in the ear piece. The vibrating metal plateor membrane 29 is firmly held between two rings 30, fixed between themetal ring 23 and the cover 26. In the casing the magnet is freelysuspended in its neutral points, the two superposed rings 31 and 32being fixed by screws 33 and 34 to two lappets 35, 36, the screws beinginsulated from the electromagnet by means of disk 37 of insulatingmaterial and of insulating linings to the screw holes. Two bolts 38 and39 effect the conducting connection of the wire line with the wire coils44, 45 of the magnet. On the rear side of the rings 31 and 32 andconnected thereto by screws 40, 41 are two angular soft iron pole pieces42, 43 arranged at right angles to the points of suspension, which polepieces carry the wire coils 44, 45, which are of exactly the same heightand have the same number of windings. Also the pole pieces 42, 43 mustbe of exactly the same height. WVhen not in use the magnet attracts themembrane 29 to its pole arms 42, 43 in consequence of which the membraneis curved and can only vibrate to one side. Of course the apparatusdescribed can be applied to all kinds of telephones, whether they betable apparatus or a wall or a box apparatus for the operators ofexchange. The size of the several parts of the transmitter and receiverare to a great extent not selected at will but also calculated accordingto laws and rules of phonology in order to obtain the greatest possibleeffect in my telephonic apparatus. Experience has proved the followingproportions to be especially favorable to the obtention of remarkablegood efiects.

Very essential for a clear transmission are the proportions of theheights of the cylindrical hollow bodies, which may be calculated in thefollowing manner, practice having shown, that these principles arecorrect. It is well known that the tone produced by llt a tuning fork isreinforced by a sounding box, if the fork is placed thereon, thereinforcement consisting in harmonic subsidiary and upper tones producedby the vibration of the box. If two or more tuning forks producing adifferent number of vibrations are however placed on a sounding box,then the original tones are reinforced and interferences appear besidesthat are audible and make the impression of shocks. Even if the soundingbox contains a partition the tones are reinforced in the same manner(according to Tyndal page 297), and the same shocks can be heard. Withseveral tuning forks and several sounding boxes the effect is increasedcorrespondingly. The transmitter and receiver in my telephonic apparatusconsist of a system of such sounding boxes. In the transmitter 3 soundinwaves in form of hollow bodies (cylinders? of the same diameter arearranged one behind the other, while the tuning forks are represented bythe sound waves produced by speaking, etc. The proportion of the sum ofthe heights of the two front hollow bodies to the height of the thirdhollow body is 2:3, in order to produce the eifect of the quinte, whichgives according to Konig the greatest effect. The sum of the heights ofthe two front hollow bodies between the metal plate 4 and the front sideof the carbon plate 3 is 8 mm., the carbon plate 2 is included in these8 mm., while the thickness of the metal plate 4 (0.05 mm.) may beneglected being too insignificant. The height of the middle spacebetween the back of the carbon plate 2 and the front of the carbon plate3 may vary slightly, according to the number of vibrations of the tone,for which the microphone is designed. For instance for a g with 400vibrations per second the height would be 4.00 mm., for a tone with 424vibrations per second 4.24 mm.

The carbon plate 2 being 1 mm. thick, the height of the first hollowbody between the metal plate 4 and the carbon plate 2 is also variableas the total sum of 8 mm. must not be exceeded. If the middle cylinderbe 3.84, 4.00, 4.24 mm. high, then the corresponding height of the firstcylinder is 3.16, 3.00, 2.76 mm., thus always giving a sum of 8 mm.,including the thickness of the carbon plate 2 which must be taken intoaccount as a partition. The space between the carbon plate 3 and themetal plate 5 is 10 mm. high, thus giving for the third hollow body including the carbon plate 3which is 2 mm. thicka depth of 12 mm. Theproportion to the two front spaces is therefore also 8:12 or 2:3. Thetwo metal plates 4 and 5 may be painted advantageously with oil color.The diameter of the hollow bodies and in consequence the diameter of thetransmitter is also regulated by the wave-length of the tone, that hasbeen selected as fundamental tone and by the octave, viz. the number ofvibrations into which the fundamental tone is to be converted. Thediameter of the transmitter is however of less importance than theproportions of the other part. The smaller the diameter the higher arethe numbers of vibrations and in consequence the tones. Very high tonesare however not well reproduced in the receiver, and experience hasshown, that the tone should not exceed the fourth octave of thefundamental tone g with 424 vibrations. The g of the fourth octave has6784 vibrations. The sound progressing within the hollow bodies with aspeed of 341.3 m. per second, this quantity must be divided through thenumber of vibrations of the highest additional tone, which it isintended to reach. For the g of the fourth octave the diameter of thetransmitter is therefore 341 300 6784: 50.3 mm.

The receiving and transmitting space proper is the middle cylinder, inwhich the carbon balls 7 are arranged in such manner, that they are freeto oscillate to and fro in consequence of the vibrations of the carbonplates 2 and 3. The conical part 8 of the carbon plate 3 has fourcircular grooves 6, the section of which is an equilateral triangle 1.92mm. base and 1.82 mm. height. Each ball has a diameter of about 1.75 mm.

The distance between the ball and the carbon plate 2 being 0.12 mm. to0.30 mm., the space between ball and the apex (viz. the lowest part ofthe groove) is 1.00 mm., if the ball enters the groove as far aspossible. After the ball has rolled out of the groove till it touchesplate 2, the space between ball and apex is 1.12 to 1.30 mm. Theoscillation of the balls may therefore reach the amount of 0.120.30 mm.In consequence of their oscillation the air behind the balls isalternately compressed and rarefied. For this reason a space must beleft between the two uppermost balls in which groove-a space equal to 1ball in the innermost and to two or more balls in the outer oneasotherwise the balls would not have free play, but would interfere witheach other and be jammed.

The balls 7 will rest against plate 2 when plate 3 is in a verticalposition. The great number of balls enables the transmitter to transformany number of vibrations of the air into electrical impulses in the mostadvantageous manner, the current passing from plate 2 to plate 3 beinginterrupted or at least considerably weakened by the resistance of thelayer of air between plate 2 and the balls. The distance between the theother.

pressed more or less and the plate 3 moved a little. The telephonereceiver consists also of two cylindrical resounding boxes, though theirconstruction differs somewhat from those of the transmitter. They haveeach an outward opening and are divided by the membrane 29. Thevibrating part of this membrane, the casing (sounding boxes) and thetransmitter have the same diameter. The diameter of transmitter andreceiver must be the same in order to reproduce the sinoides of thecarbon plates of the transmitter on the membrane of the receiver. Theratio of the heights of the hollow bodies of the receiver is 8:17, theheight of the front hollow body being counted from the outer edge of theopening in the ear piece to the membrane including this, which is 0.25mm thick, while the back hollow space is counted from the back of themembrane 29 to the outer edge of the opening 2% in the back wall 25.

Any harmonic proportion may prevail between the heights of the tworesounding boxes of the receiver, for instance 12:8 or 16:8. If theproportion 12 8representing a pure quinte-were selected, the soundproduced would be an octave below the most piercing tone produced in thetwo hollow bodies by the vibrations of the membrane. At small distancesthe tone, which is audible at the back of the transmitter would not beweakened enough. The proportion 17:8 is especially favorable being thetierce of the double octave, by which tones are produced, which are twooctaves lower.

In the receiver as in the transmitter not only is the sound reinforcedby the hollow bodies, but the same interferences in the sound waves.viz. the shocks above described are produced. The two hollow bodiesproduce tones, the difference of which is slightly above an octave. Inthis case shocks are produced according to Kiinig, which cause the toneto appear sharp and clear and which reinforce the tone produced in theear piece, the difference of form of the two hollow bodies of thereceiver and the cause of the sound audible in front being far louderthan that audible through the opening in the back of the receiver. Thisis of great im portance for small distances, where the sound received bythe microphone is reproduced in such strength in the telephone receiverthat it would affect the ear painfully, if the front opening were used.It is there fore advisable to use the back opening for small distancesreserving the use of the ear piece for speaking at long distances. Ofthe sound waves produced by membrane 29 a part is reflected by thearched cover 26 till they are able to quit the receiver by the opening28.

It is of an importance, that the formation of sound is disturbed in noway inside the casing. For this purpose the magnet must be able tooscillate freely, which end is attained by suspending it in the neutralline. The steel membrane 29 is continually attracted by the magnet andrests against the poles. The system oscillates together and is onlyseparated from time to time, the magnet acting both in consequence ofits own magnetism and of the electromagnetism produced by the wire coils14: and as.

In consequence of the constant attraction of the magnet the membrane 29is slightly curved, the height of the curve being 0.12 to 0.30 min,meaning that without the at traction of the magnet the distance betweenthe membrane 29 and the pole pieces a3 would reach this amount. The sizeof the curvature is equal to the play of the balls 7 of the transmitter.The rings 31 and 32 of which the magnet is composed and the two lappets35, 36 are each 2 mm. thick, while the pole pieces 12, 4-3 are slightlythicker 2.25 mm. Their wire coils must be equally high and contain thesame number of windings of the same thickness of wire. The externaldiameter of the magnet is 18.48 mm., and the internal 28 mm. Thedifference between the upper surfaces of the ring 32 and of the polepieces 42, 13 is 6.78 mm. The screws 33, 34 by which the magnet issuspended are of a different kind of steel in order to avoid adeflection magnetic lines of force.

My telephonic apparatus acts in the following manner: The sound wavesentering the mouthpiece 9 of the microphone transmitter cause the metalplate 4 to vibrate. These vibrations pass on in succession to the air ofthe first hollow body, the carbon plate 2, the air of the middle hollowbody, the carbon plate 3, the air of the last hollow body and the plate5. The sound waves being reflected within each of these spaces,interferences appear, causing additional and differential tonesaccording to Helmholz or tone shocks (sons (Zea battements) according toKonig. My experiments have shown that additional and differential tonesand tone shocks are formed. At all events only harmonic upper tones areproduced viz: tones with a great number of vibrations per second, whichcause the plates 2 and 3 to oscillate violently and the balls 7 to play.The microphone produces therefore an extremely great number of electricimpulses, which pass through the line in the usual manner to thetelephone receiver. The magnetism of the electroma net is changedconstantly by the electric impulsesincluding currents passing throughthe coils 14C, 15. The membrane 29 begins to vibrate and with it thesystem of magnet and membrane. Perhaps the membrane may also beseparated at times from the magnet and then again united with 1t. Thesound produced is very clear,

111 UUllfiUliLLbLlUU U1. bll d .uiuuuuig UUIIUILL UU ing very weak andof the possible oscillation of the plate being very small. It isdoubtful, whether the oscillations of the membrane are distinctoscillations or whether they must be regarded as merely molecularoscillations. There can be however no doubt of the good result. Thesound waves are then reinforced by the resounding boxes, which causealso interferences and shocks.

The advantages of my telephonic apparatus are very great, the mostessential consisting in the great distance, to which it allows to speak,distances, which up to the present were quite out of question.Experiments have shown the possibility of such transmission up todistances of at least 2000 km. The adoption of harmonic proportionexcludes the possibility of dishar monic subsidiary or upper tones. Thisis another great advantage as these tones are the chief reasons, thattelephonic apparatus fail at great distances.

The construction of the microphone transmitter and the telephonereceiver is very simple and each part easily accessible. My apparatusmay be therefore employed for every kind of telephones, whether they betable apparatus or a wall or a box apparatus for the operators ofexchange.

The arrangements and sizes mentioned above may vary according tocircumstances. It is for instance not absolutely necessary, that themicrophone should have three hollow bodies, two of them being alsosufiicient, though the effect is then smaller. The proportion betweenthe heights of the two front hollow bodies differs according to thefundamental tone. If, for instance other nations or other races haveanother fundamental tone, then the apparatus would have to be arrangedto suit this tone. If a tone with more vibrations is to be produced inthe transmitter, its diameter and consequently the diameter of thereceiver would have to be altered.

Instead of the quint another harmonic proportion may be selected for theheights of the hollow bodies, for instance a tierce. If music is to bereproduced, for instance an opera or a concert, the sound may bereceived by several microphone transmitters that are regulated fordifferent fundamental tones. Of course a corresponding number oftelephone receivers would be required for the reproduction.

What I claim as my invention and desire to secure by Letters-Patent is:

1. A telephone system having the transmitter and receiver provided withhollow bodies or chambers arranged close to each other and harmonicallyproportioned one to the other.

2. A telephone system having a trans mitter and receiver provided withhollow UULLLUD Ul' CllulllUEl'fi ill'liillgfiu CLUSU LU 8min. other withthe heights of the hollow bodies in the transmitter and receiverrespectively showing such dimensions as to present harmonic proportionsamong each other.

3. A telephone system having a transmitter and receiver with hollowbodies or chambers arranged close to each other with the heights of thehollow bodies in the transmitter and receiver respectively showing suchdimensions as to represent harmonic proportions among each other, thehollow bodies of the transmitter having the same diameter and the hollowbodies of the receiver having at the diaphragm the same diameter asthose of the transmitter.

4:. A telephone system having a transmitter and receiver with hollowbodies or chambers arranged close to each other with the heights of thehollow bodies in the transmitter and receiver respectively showing suchdimensions as to represent harmonic proportions among each other, thehollow bodies of the transmitter having the same diameter and the hollowbodies of the receiver having at the diaphragm the same diameter asthose of the transmitter, said diameter being related to the fundamentaltone for which the apparatus is designed.

5. A telephone transmitter composed of two carbon plates, and metalplates, one in front of and the other behind the carbon plates andspaced therefrom, the said carbon and metal plates being spaced apart toform closed chambers the heights of which are harmonically proportionedone to the other.

6. A telephone transmitter comprising diaphragms or plates arranged toform three cylindrical chambers the central one of which constitutes themicrophonic element of the transmitter, and the several chambers havingtheir heights harmonically related one to the other.

7. A telephone transmitter comprising diaphragms or plates arranged toform three low cylindrical chambers, the central one of whichconstitutes the microphonic element of the transmitter, the sum of theheights of the central chamber and one of the other chambers bearing theproportion to the height of the other outer chamber of two to three.

8. A telephone transmitter having a thin flat carbon diaphragm, anothercarbon diaphragm with a thickened central portion in which is formed aplurality of concentric grooves varying in number according to the toneupon which the instrument is based and series of carbon balls, oneseries in each groove and engaging the first named carbon diaphragm.

9. A telephone transmitter having hollow bodies, a case provided withapertures, at

the front and back, of different areas, two

JllUl/(klliu LLl Cl/Pllldlllb ill LllU Uu/DU LUbPUULILVBJ-y adjacent tothe apertured front and back, two spaced carbon diaphragms between themetal diaphragms and of substantially the same diameter as the metallicdiaphragms, and balls loosely confined between the carbon diaphragms theheights of the hollow bodies being harmonically related one to theother.

10. A telephone transmitter having hollow bodies, a case provided withfront and back apertures of different areas, two metallic diaphragins inthe case respectively adjacent to the apertured front and back, twospaced carbon diaphragms between the metal diaphragms and ofsubstantially the same diameter as the metallic diaphragms, ballsloosely confined between the carbon diaphragms, the heights of thehollow bodies being harmonically related one to the other and a wiregauze screen between each metal diaphragm and the respective mouthaperture.

.LL- IL LUlUlJllUllB SySLUIII UUIIlPl'lSlllg a transmitter provided withmeans for con- 25 verting sound waves into interference shocks or blowsand directing them against the microphonic side of said transmitter, anda receiver having means for reproducing the original sounds from thetransmitted shocks 30 or blows.

12. A telephone system comprising a transmitter provided with means forconverting sound waves into interference shocks or blows and directingthem against the mi- 35 crophonic side of said transmitter, and areceiver having means for reproducing the original sounds from thetransmitted shocks or blows, the transmitter and receiver beingharmonically proportioned one to the other.

In witness whereof, I subscribe my signature, in presence of twowitnesses.

VICTORIEN TARDIEU.

\Vitnesses:

CHARLES SHUMPE, VICTOR H. MORGAN.

